U.S. patent application number 12/430938 was filed with the patent office on 2009-12-03 for activated carbon filter unit for a tank system.
This patent application is currently assigned to A. Kayser Automotive Systems GmbH. Invention is credited to Stephan Ammermann, Heiko Freter.
Application Number | 20090293726 12/430938 |
Document ID | / |
Family ID | 41254138 |
Filed Date | 2009-12-03 |
United States Patent
Application |
20090293726 |
Kind Code |
A1 |
Ammermann; Stephan ; et
al. |
December 3, 2009 |
ACTIVATED CARBON FILTER UNIT FOR A TANK SYSTEM
Abstract
An active carbon filter unit for a tank system consists of a
housing (13) in which two chambers (31, 32) are formed, carrying an
active carbon filling, which form a section of a flow path which at
its one end leads via a valve (6) and an air filter (7) into the
ambient atmosphere and at its other end leads via a valve (9) and a
non-return valve (10) to a connection for producing an
underpressure or into the suction region of an internal combustion
engine and via a connection (17) into the tank system. The valves
(6, 9), the non-return valve (10) and a housing part (27) receiving
the electrical connections thereof are part of a uniform control
module (15), which is exchangeably inserted into a recess (14) of
the housing (13). The control module (15) is equipped with almost
all functional elements of a technical nature relating to
measurement, control and energy supply which are necessary for an
aeration and air removal operation, a flushing operation directed
to a regeneration of the active carbon, and a tightness check of
the tank system.
Inventors: |
Ammermann; Stephan;
(Gottingen, DE) ; Freter; Heiko; (Einbeck,
DE) |
Correspondence
Address: |
FOX ROTHSCHILD LLP
2000 MARKET STREET, 10th Floor
PHILADELPHIA
PA
19103
US
|
Assignee: |
A. Kayser Automotive Systems
GmbH
Einbeck
DE
|
Family ID: |
41254138 |
Appl. No.: |
12/430938 |
Filed: |
April 28, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61056960 |
May 29, 2008 |
|
|
|
Current U.S.
Class: |
96/113 |
Current CPC
Class: |
F02M 25/0836 20130101;
F02M 25/0854 20130101 |
Class at
Publication: |
96/113 |
International
Class: |
B01D 53/04 20060101
B01D053/04 |
Claims
1. Active carbon filter unit for a tank system consisting of a
housing (13), having at least one chamber (31, 32) able to be
flowed through, intended to receive an active carbon filling, in
which a flow path is arranged, incorporating this chamber, which is
able to be brought in connection with the tank system, the ambient
atmosphere and a connection for producing an underpressure,
according to the execution of an operation for air removal,
aeration or flushing or of a tightness check, wherein the flow path
is equipped with a first valve (6) for opening and closing the
connection of the flow path with the ambient atmosphere and with a
second valve (9) for opening and closing the communication to the
connection for producing an underpressure, characterized by a
control module (15), in operative connection with the housing (13),
into which at least the valves (6, 9) are incorporated.
2. Active carbon filter unit according to claim 1, characterized in
that the control module (15) is detachably connected with the
housing (13).
3. Active carbon filter unit according to claim 1, characterized in
that the control module (15) is able to be inserted into a recess
(14) of the housing (13).
4. Active carbon unit according to claim 1, characterized in that
in addition a non-return valve (10) is incorporated into the
control module (15) and namely into the communication leading to
the connection for producing an underpressure.
5. Active carbon unit according to claim 1, characterized in that a
sensor (12) for detecting the pressure of the gas atmosphere within
the tank system is incorporated into the control module (15).
6. Active carbon unit according to claim 1, characterized in that a
sensor (4) for detecting the temperature of the gas atmosphere
within the tank system is incorporated into the control module
(15).
7. Active carbon unit according to claim 1, characterized in that
an air filter (7) is incorporated into the control module (15).
8. Active carbon unit according to claim 1, characterized in that
an air filter (7) is an integral component of the housing (13).
9. Active carbon unit according to claim 1, characterized in that
the control module (15) is constructed as an elongated base body
(18), which is in communication with a housing part (28)
integrating at least the electrical connections of the valves (6,
9).
10. Active carbon unit according to claim 9, characterized in that
the electrical measurement, control and/or energy supply
connections intended for the sensor/sensors (4, 12) are
additionally arranged in the housing part (28).
11. Active carbon unit according to claim 1, characterized in that
in the control module (15) a measurement chamber (43) is arranged,
which is in operative connection at least with one of the sensors
(4, 12) and which is in continuous connection with a chamber (40)
directing the gas atmosphere of the tank system, constituting a
section of the said flow path.
12. Active carbon unit according to claim 11, characterized in that
the chamber (38) is formed inside the control module (15).
13. Active carbon unit according to claim 1, characterized in that
the recess (14) of the housing (13), intended to receive the
control module (15), is provided with openings (41, 39) to
constitute a connection with the at least one chamber (31, 32)
carrying an active carbon filling, within the framework of the said
flow path.
14. Active carbon unit according to claim 1, characterized by
connections (17, 19) for ducts intended to carry a gas, leading to
the connection for producing an underpressure or to the tank
system.
15. Active carbon filter unit according to claim 2, wherein the
control module (15) is able to be inserted into a recess (14) of
the housing (13).
16. Active carbon unit according claim 2, further comprising a
non-return valve (10) incorporated into the control module (15) and
namely into the communication leading to the connection for
producing an underpressure.
17. Active carbon unit according to claim 3, further comprising a
non-return valve (10) incorporated into the control module (15) and
namely into the communication leading to the connection for
producing an underpressure.
18. Active carbon unit according to claim 2 further comprising a
sensor (12), for detecting the pressure of the gas atmosphere
within the tank system, incorporated into the control module
(15).
19. Active carbon unit according to claim 3, further comprising a
sensor (12), for detecting the pressure of the gas atmosphere
within the tank system, incorporated into the control module
(15).
20. Active carbon unit according to claim 4, further comprising a
sensor (12), for detecting the pressure of the gas atmosphere
within the tank system, incorporated into the control module (15).
Description
[0001] The invention relates to an active carbon unit in accordance
with the introductory clause of Claim 1.
[0002] For reasons of environmental protection, an escape of
hydrocarbon components must be restricted from the fuel container
of a tank system which is connected with the ambient atmosphere to
balance out different filling levels, temperature fluctuations,
evaporations etc. Legal requirements also stipulate a tightness
check of the tank system which is to be carried out in an automated
manner.
[0003] From the document U.S. Pat. No. 6,390,073 B1 a tank system
of a motor vehicle is known with an active carbon filter unit which
consists of a housing, forming internally two chambers intended to
receive active carbon, which are connected with each other via a
gap, wherein one chamber is provided with connections for those
ducts which are connected with the head space of a fuel container
and those which are connected with a suction region of an internal
combustion engine. The other chamber, at its end facing away from
the gap and with the intermediate arrangement of a first
electrically actuatable valve and of a filter, is provided with an
air-removal duct leading into the free atmosphere. This first valve
is designed as a structural unit which is able to be inserted into
a cylindrical recess of the housing and is constructed such that it
opens in the idle state and closes when live. It is additionally
designed with the requirement that the opening process, which is
initiated by a spring, is assisted by the vacuum of the said
suction region. A second electrically actuatable valve is situated
in the duct which connects the first chamber with the said suction
region.
[0004] During refuelling when the engine is at a standstill, the
first vale is in the open position, so that air enriched with
hydrocarbons can be displaced out of the head space of the fuel
container and can escape into the atmosphere via the chambers,
containing active carbon, and the filter, with a hydrocarbon
component being retained adsorptively. When the engine is running,
vice versa the air is drawn in via the filter and the open first
valve, wherein in the region of the chambers hydrocarbon components
which are still bonded are entrained as a result of desorption and
are introduced via the open second valve into the combustion
chamber of the engine.
[0005] Through the fact that firstly the first and subsequently the
second valve are transferred into a closed position, so that the
tank system, when the engine is running, is temporarily entirely
exposed to the effect of the engine vacuum, a defined underpressure
is developed within the tank system, so that the course of the
reduction of a differential pressure to the ambient atmosphere
provides indications for any unacceptable leakages which may be
present.
[0006] A feature of this known active carbon filter unit is that to
constitute the different forms of operation of aeration and air
removal, of flushing and of a tightness check within the tank
system a cooperation of structural elements, to be mounted
individually, is also necessary outside the active carbon filter
unit. In individual cases, this can entail a great effort with
regard to installation and in the tightness check, which is
ultimately based on a comparison with a standard pressure
distribution, it can make costly adjustment operations necessary
which are adapted individually to the installation situation. A
function check of the cooperating components of the tank system
during the air removal operation or a flushing operation and a
tightness check can also prove to be comparatively laborious.
[0007] With this background, the object of the invention is to
develop an active carbon unit of the type described in the
introduction with regard to a simplified manageability concerning
installation, in particular with regard to a simpler structure of
the tank system. This problem is solved in such an active carbon
unit by the features of the characterizing clause of Claim 1.
[0008] Accordingly, the concept of a control module, hence of a
structural element which is, moreover, separable from the housing
of the active carbon unit conceptually and concretely, into which
at least the valves constituting or separating the connections to
the ambient atmosphere and to the suction region of the internal
combustion engine are structurally integrated, is essential to the
invention. For the construction of the tank system, the
installation of valves is dispensed with in the course of ducts
through which these connections are constituted. This brings about
a simplification on installation, but in particular the advantage
that the functionality of valves and sensors is able to be checked
outside the active carbon filter. Furthermore, a structural unit
consisting of the housing with inserted control module, can also be
checked before installation into a vehicle. In each case, the
control module is in operative connection with the housing and can
be exchanged easily in the case of breakdown. The type of
connection can consist of an aggregation with regard to
components--however, the connection can be of a merely functional
nature.
[0009] According to the features of Claims 2 or 3, the control
module can be insertable into a recess of the housing and in this
inserted state can be able to be secured reliably in a suitable
manner. It can also be in detachable connection with the housing in
another manner. For example, a separate housing which is in
detachable connection with the housing of the active carbon filter
unit can be provided for the control module.
[0010] The features of Claims 4 to 6 are directed to a further
development of the control module, which aim to include further
functions of the tank system of a technical nature concerning
control or measurement or respectively monitoring. In this context,
it is essential that these are integrated in an exchangeably
arranged structural group. In detail, this can be a non-return
valve here, the use of which is known as such, namely in order to
absorb pressure peaks of the combustion chamber of the engine. It
may further concern sensors for picking up pressure and temperature
of the gas atmosphere of the tank system, hence as a whole all the
structural groups or structural elements inhibiting or releasing
the gas flow within the tank system and detecting its data, in
particular of a thermal nature. These are therefore combined in the
control module, so that the structure of the housing is, moreover,
comparatively simple.
[0011] The features of Claims 7 and 8 are directed to variants for
accommodating the air filter. This can likewise be included into
the control module--however, it can also be constituted by a part
of the housing.
[0012] The features of Claims 9 and 10 are directed to further
features of the control module. Accordingly, a housing part is
situated on this, which forms an interface for all electrical leads
of the technical type concerning measurement, control and energy
supply, with a plug connection being able to be provided here, for
example. This uniform electrical connection site offers, at the
same time, possibilities for a standardized fault check in the
dismantled state of the control module.
[0013] The features of Claims 11 and 12 are directed to the
development of the control module, in so far as its suitability is
concerned for carrying out a tightness check of the tank system,
running in an automated manner. For this purpose, a measurement
chamber is arranged, the gas atmosphere of which, moreover,
corresponds to that of the tank system and which is in operative
connection with the said sensors. To carry out a tightness check,
which is based on the temporary constitution of a partial vacuum by
means of the suction region of the internal combustion engine and
the evaluation of its chronological sequence, a superordinate
control containing a computer system is necessary, which triggers
the process of the tightness check and, by means of comparative
data, makes possible a statement concerning the result of the
tightness check.
[0014] The features of Claims 13 and 14 are directed to further
developments of the control module or of the housing, the at least
one chamber of which, holding an active carbon filling, in each
case forms a section of the flow path which is to be constituted
within the active carbon unit, and namely both during the aeration
and air removal of the tank system and also during the tightness
check.
[0015] By means of the above explanations, it can be seen that by
the active carbon unit according to the invention a structural
element is made available which is distinguished by a higher degree
of aggregation of functional elements of a tank system compared
with the prior art. In particular, due to the exchangeability of
the control module, advantages are produced of a technical nature
concerning installation, and also in the diagnosis of faults,
because a checking of all functions of the control module can be
carried out in the dismantled state.
[0016] Furthermore, the advantage is produced of a housing,
moreover, which is provided very simply, so that it is possible to
be able to use the control module in different housings, which only
have to be equipped with means for fastening or holding and with
interfaces of a flow path for the integration of a chamber
containing active carbon.
[0017] The invention will be described in further detail below with
reference to the example embodiment illustrated in the drawings, in
which:
[0018] FIG. 1 shows a circuit diagram of a tank system of a motor
vehicle, including an active carbon filter unit;
[0019] FIG. 2 shows a perspective illustration of an active carbon
filter unit according to the invention;
[0020] FIG. 3 shows a perspective illustration of the control
module of the active carbon filter unit according to FIG. 2;
[0021] FIG. 4 shows an enlarged partially sectional illustration of
the active carbon filter unit with inserted control module
according to a sectional plane IV-IV of FIG. 2;
[0022] FIG. 5 shows a perspective illustration of the active carbon
filter unit, in which the control module has been removed;
[0023] FIG. 6 shows an illustration of the active carbon filter
unit with inserted control module in a vertical sectional
plane;
[0024] FIG. 7 shows an illustration of an active carbon filter unit
with inserted control module during a flushing phase in a vertical
sectional plane;
[0025] FIG. 8 shows an illustration of an active carbon filter unit
with inserted control module during an air-removal phase in a
vertical sectional plane;
[0026] FIG. 9 shows a partial illustration of an active carbon
filter unit with inserted control module in a sectional plane IX-IX
of FIG. 8.
[0027] In FIG. 1 the fuel container of a tank system is designated
by 1, the head space of which is connected via a ventilation duct 2
with an active carbon unit 3. A sensor detecting the temperature of
the gas atmosphere of the tank system is designated by 4, the
function of which will be described in further detail below.
Practically, the ventilation duct can also be arranged at a
different location of the tank system or of a tank duct.
[0028] A further air duct 5, connected to the active carbon unit,
leads into the free atmosphere via a valve 6 and an air filter 7.
The active carbon unit 3 connects with the suction pipe 11 via
another air duct 8, in the course of which a valve 9 and a
non-return valve 10 are arranged following one another in the
direction of the suction pipe 11 of an internal combustion engine
which is not illustrated in the drawing.
[0029] A sensor, connected with the active carbon filter unit,
intended to detect a differential pressure between the tank system
and the surrounding atmosphere, is designated by 12, the function
of which will likewise be described in further detail below.
[0030] As can be seen with the aid of FIGS. 2, 3 and 5, the active
carbon filter unit 3 consists of a housing 13, in the upper region
of which a mounting 14 is formed for a control module 15, which is
insertable detachably into this recess 14 and is fixed in the
inserted position in a suitable manner which is not illustrated in
the drawing. The housing 13 is provided with connections 16 for the
air duct 5 and 17 for the duct 2.
[0031] The control module 15 consists of an elongated, globally
cylindrical base body 18, at one end of which a connection 19 is
situated for the duct 8, with reference being made, moreover, to
FIG. 4 to describe its configuration.
[0032] According to the invention, the valve 6 is integrated into
the control module 15 and is characterized by a valve plate 20
which is to be actuated electromagnetically and is movable in the
axial direction of the base body 18, which valve plate 20 is
arranged in the input region of the air filter 7, for cooperation
with a valve seat surface 21 in the form of a circular ring.
[0033] According to the invention, the valve 9 is integrated into
the control module 15 and is characterized by a valve plate 22, to
be actuated electromagnetically and likewise movable in the axial
direction of the base body 18, which is arranged for cooperation
with a valve seat surface 24 formed by an end face of a tube
element 23.
[0034] According to the invention, finally, the non-return valve 10
is integrated into the control module 15 and is characterized by a
valve plate 25, likewise movable in the axial direction of the base
body, which is arranged for cooperation with a valve seat surface
26 formed by the other end face of the tube element 23 and in the
illustration in the drawing according to FIG. 4 in the direction on
the right side lies under spring pre-stressing against the said
valve seat surface.
[0035] A housing part formed on the base body 18, integrating at
least the electrical connections of the valves 6, 9, is designated
by 27.
[0036] In this respect, it is essential that the control module 15
is a component which is able to be inserted independently
detachably into the recess 14 of the housing 13, and is therefore
arranged so as to be exchangeable and in particular able to be
produced independently of the housing. This unites several
structural elements which are required for the operation of the
tank system, including the control, measurement and monitoring
functions associated therewith.
[0037] A housing part which is likewise arranged on the base body
18 with intermediate arrangement of a cylindrical section 29 is
designated by 28, in which the sensors 4, 12 are held. Connections
for measurement and/or energy supply lines of these sensors can
likewise be held in the housing part 27.
[0038] As can be seen by means of FIGS. 4 and 6, the housing 13 is
divided by an intermediate wall 30 into two chambers 31, 32 which
are filled with active carbon and which in the region of the base
33 of the housing are connected with each other via an opening 34
or opening arrangement making possible a passage of air. Inside the
housing 13, also delimited on the upper side by the facing wall of
the recess 14, a chamber is arranged, delimited on the underside by
an intermediate base 35, which is divided into two chambers 36, 37
by the intermediate wall 30.
[0039] On the side of the air filter 7, delimited substantially by
the walls of the recess 14 and those of the control module 15, a
chamber 38 is arranged, which is in continuous connection with the
chamber 37 via an opening 39 and which, moreover, is connected with
the ambient atmosphere via the air filter 7, according to the
position of the valve 6.
[0040] On the side of the housing part 27, inside the control
module 15 a chamber 40 is arranged, in continuous connection with
the chamber 36 via openings 41, communicating with each other, of
the base body 18 of the control module and of the walls of the
recess 14. The chamber 40, moreover, is in continuous communication
with the connection 17, according to the position of the valve 9
and of the non-return valve 10. A constant connection exists
between the chamber 36 and the connection 17, which is intended for
the connection with the head space of the fuel container 1 (FIG.
1).
[0041] Openings in the intermediate base 35, via which continuous
connections are arranged between the chambers 32, 27 and 31,36, are
not illustrated in the drawing.
[0042] As can be seen with the aid of FIG. 9, the chamber 38 is, in
addition, in continuous connection via an opening 42 with a further
measurement chamber 43, which is intended for the detection of
pressure and temperature of the gas atmosphere prevailing in the
chamber 38 and is accordingly in operative connection with the
sensors 4, 12.
[0043] FIG. 8 shows the operating state intended for the aeration
and air removal of the tank system, wherein the valve 6 is opened
and the valve 9 and the non-return valve 10 are closed. According
to the directions of the arrow 44, a continuous connection exists,
making possible a gas exchange, starting from the head space of the
fuel container 1 or of a site of the tank system having the same
effect, via the connection 17, the chambers 36, 31, 32, 37 and the
air filter 7 with the ambient atmosphere. Air laden with
hydrocarbons from the head space can therefore flow out, according
to the prevailing pressure- and temperature conditions under
adsorptive bonding of a hydrocarbon component in the chambers 31,
32 until reaching a pressure equilibrium with the environment. This
is a state which exists for example when refuelling the
vehicle.
[0044] FIG. 7 shows the operating state intended for flushing the
active carbon unit, where the engine is running, so that the
non-return valve 10 and the valve 9 are in the open position, so
that the chambers 40, 36, 31, 32 and 37 are acted upon with the
underpressure of the suction pipe 11 of the engine via the
connection 19. This underpressure brings about a drawing in of
ambient air with through-flow of the chambers 31, 32, with a
hydrocarbon content which is bonded here being held and supplied
via the connection 19 to the combustion chamber of the engine.
According to the prevailing pressure conditions, in this operating
state likewise a drawing in is brought about via the connection 17
of air laden with hydrocarbons which, however, together with the
air received via the air filter 7, is introduced into the
combustion chamber. In each case, the active carbon component, held
in the chambers 31, 32, undergoes a regeneration as a result of
removal of the hydrocarbon component which was previously
adsorptively bonded.
[0045] FIG. 6 shows the operating state intended for checking the
tightness of the tank system, which is carried out automatically
according to a presettable time interval with the cooperation of a
superordinate control. For this purpose, with the engine running,
firstly the valve 6 is transferred into the closed position which
is shown, so that the tank system is acted upon with the
underpressure of the suction pipe 11 via the connection 19 and a
defined underpressure develops within the tank system. Then the
valve 9 is also closed and subsequently by means of a measurement
of the chronological pressure pattern by means of the sensor 12 a
check is carried out as to whether if applicable a leakage exists
which is not to be tolerated. The evaluation of the measurement
result can be further improved by simultaneous measurement of the
temperature of the gas atmosphere. Factually, the evaluation of the
measurement result which is thus obtained is carried out in an
automated manner by means of stored sets of comparative data also
taking into account the temperature influence, with the result
being able to be presented visually in a suitable manner.
LIST OF REFERENCE NUMBERS
[0046] 1 Fuel container
[0047] 2 Ventilation duct
[0048] 3 Active carbon unit
[0049] 4 Sensor
[0050] 5 Air duct
[0051] 6 Valve
[0052] 7 Air filter
[0053] 8 Air duct
[0054] 9 Valve
[0055] 10 Non-return valve
[0056] 11 Suction pipe
[0057] 12 Sensor
[0058] 13 Housing
[0059] 14 Mounting
[0060] 15 Control module
[0061] 16 Connection
[0062] 17 Connection
[0063] 18 Base body
[0064] 19 Connection
[0065] 20 Valve plate
[0066] 21 Valve seat surface
[0067] 22 Valve plate
[0068] 23 Pipe element
[0069] 24 Valve seat surface
[0070] 25 Valve plate
[0071] 26 Valve seat surface
[0072] 27 Housing part
[0073] 28 Housing part
[0074] 29 Intermediate section
[0075] 30 Intermediate wall
[0076] 31 Chamber
[0077] 32 Chamber
[0078] 33 Base
[0079] 34 Opening
[0080] 35 Intermediate base
[0081] 36 Chamber
[0082] 37 Chamber
[0083] 38 Chamber
[0084] 39 Opening
[0085] 40 Chamber
[0086] 41 Opening
[0087] 42 Opening
[0088] 43 Measurement chamber
[0089] 44 Arrow
[0090] 45 Arrow
* * * * *